It’s Monday Marvels and today’s place of honor is reserved to the dog’s lungs. We often take a dog’s lungs for granted except when they trigger coughing or wheezing, making us worry about our dog’s health. The dog’s lungs are vital organs, and as such, they require great care to ensure they function and continue to function properly. There are many disorders out there that can affect the lungs, so it’s best to take good care of them and immediately report to the vet any changes. But let’s allow the dog’s lungs to do the talking, so we can get better acquainted with them.
Hello, it’s your dog’s lungs talking! There are two of us, the right lung and the left one, and just like in humans, they’re divided into several lobes. If you look closely at my air passages, you’ll notice that they appear like an upside-down tree. My larger branches are the bronchi, and then there are the finer branches which are my bronchioles.
Then, if you were to look at things microscopically, you would notice that my bronchioles end into these teeny tiny structures known as the alveoli which are like grape-like bunches of air. Each alveolus is covered with capillaries that receive blood from the heart.
My biggest job is to allow your dog to breathe well. When your dog inhales, fresh air enters his nose or his mouth, then it reaches the pharynx, the larynx and the trachea, also known as the windpipe. As the name implies, the windpipe is a tube that carries the air from the nose all the way down to me through the bronchi and bronchioles.
At the level of the alveoli, the fresh oxygen-rich air is absorbed, while the used air is discarded by passing through (this time in reverse order) from the bronchi all the way back to the nose where it is exhaled. Right beneath me is the diaphragm, a dome-shaped muscle that helps your dog inhale and exhale effectively.
I am an Exchange System
I do much more than supplying oxygen, I also work as an important exchange system replacing carbon dioxide with oxygen. When the heart sends me the dark blood composed of carbon dioxide, I replace it with bright red, oxygen-rich blood that is then sent to all parts of your dog’s body giving vital energy to his cells. Cells though produce carbon dioxide, a waste gas, that needs to be removed, which happens when your dog exhales. Every day, your dog inhales and exhales hundreds of times. According to Dr. Debra Primovic, the average breathing rate in dogs is estimated to be 10 to 30 breaths per minute.
“Count the number of breaths your pet takes in one minute. Avoid counting when your dog is panting. A good time to count the normal breathing rate is when your dog is asleep.” ~Dr. Debra Primovic
You might already know that your dog doesn’t sweat as effectively as you do. Humans sweat a lot through their skin. While dogs sweat a bit from their paws, their main cooling system is provided by panting. When your dog pants, he is breathing faster, and therefore is removing the warm air from his body (ever felt how warm that air is when he pants in your face?). As the warm air is removed, it’s replaced with the cooler air from the outside.
If the air outside though is very hot and humid, I might be unable to help your dog cool down, so be careful not to overheat your dog! And what about when your dog romps in the yard or chases a squirrel? When your dog exerts himself, the brain tells me to work faster. Let him lie down though to snooze, and the brain will tell me to slow down.
Everyday I risk being exposed to triggers that could lead to problems. Bacteria, viruses, fungi, dust, chemical particles, you name it! Luckily, most are trapped by the mucous lining of the nasal passages before they reach me. Cilia, special mucous-covered hairs that resemble a field of grass as seen in the picture, also help trap foreign particles and germs before the particles make it to me. Not to mention, the immune system also attempts to destroy certain microorganisms.
However, sometimes these harmful entities still manage to make it my way. When this happens, I get irritated, even inflamed. Coughing or sneezing may sometimes help expel these entities, but sometimes this isn’t enough. Some small particles may still make it through and wreck havoc.
You see, dogs like to use their powerful sniffers, and sometimes, the may inhale spore-like particles of harmful fungi that inhabit the soil. Because these particles are tiny, they are able to reach me and cause great havoc. Histplasmosis, blastomycosis and coccidioidomycosis are some fungal infections dogs may get if they live in areas where these harmful fungal spores thrive.
Normally, the dog’s immune system should keep harmful bacteria and viruses out of my way, but if the immune system is for some reason weak, as often seen in puppies, and sometimes in older dogs, bacteria may reach the respiratory system. The distemper or parainfluenza virus may weaken the immune system enough to cause serious problems. Affected dogs may develop a sudden onset of a runny nose, sneezing, fever, lethargy and general malaise.
There are many things that can go wrong with me. You see, my alveoli are meant to fill up with air, but if they end up filling up with fluid, this leads to problems as it prevents oxygen from being absorbed into your dog’s bloodstream. How does fluid end up in the wrong place? It can happen with aspiration pneumonia, heart disease, drowning just to name a few. Because I am a vital organ, Mother Nature made sure to protect me by shielding me with a strong ribcage, but if a dog gets hit by a car, I may still get damaged. If a rib fractures and punctures me, air can escape from the area around me causing me to collapse, a condition known as pneumothorax.
If your dog for a reason or another is unable to breathe well, his body may not receive enough oxygen. Carbon dioxide may accumulate causing signs of trouble. If your dog’s gums appear pale, gray or blue, that’s a sign they lack oxygen. See your emergency vet immediately if you notice abnormal gum color in your dog. Trouble breathing and coughing in dogs is often associated with respiratory disease, but it can also be a symptom of something else such as congestive heart failure.
As seen, I play a very important role in your dog’s health! From the day your dog was born, I will be working hard day and night. Make sure you protect me as much as you can. Keep your dog away from excessive dust, and don’t forget about smoke. Dogs suffer from the effects of second-hand smoking just as humans do! Don’t forget to keep your dog’s teeth in good shape. According to VCA Animal Hospitals, dental disease ups the chances for bacteria to reach me and cause a serious secondary infection. And of course, see your vet promptly at the first signs of trouble!
I hope this helped you get more acquainted with me! Living out in the boonies makes people often forget about me, but I am always here, diligently doing my work from your dog’s first breath, to his very last.
Your Dog’s Lungs
Did you know? The dog’s respiratory system is divided in the upper respiratory tract comprising the nose, nasal sinuses, throat and trachea, and lower respiratory tract comprising the bronchi and bronchioles and the alveoli.
- Pet Education, Respiratory System: Anatomy & Function in Dogs, by Race Foster DVM, retrieved on February 29th, 2016
- Merck Veterinary Manual, Introduction to Lung and Airway Disorders of Dogs, retrieved on February 29th, 2016
- Ciliated and non-ciliated cells on lungs, public domain.
- Lungs diagram with internal details, by – Patrick J. Lynch, medical illustrator, CC BY 2.5